Full-automatic underway ADCP hydrological cableway flow measurement accurate positioning system and control method thereof

Abstract

The invention discloses a full-automatic underway ADCP hydrological cableway flow measurement accurate positioning system and a control method thereof, and relates to the field of water conservancy and hydrology. A water level reading module and a voice broadcast module are additionally arranged, a programmable logic controller is used as a control unit, a frequency converter is used as an execution unit, and the output frequency of the frequency converter is adjusted through a PLC; precise control over the whole operation process of the suspended working platform is achieved. According to the flow measurement process, the ADCP suspended working platform motion is divided into an air operation stage and a water surface dragging stage, a sliding differential control algorithm is adopted during air motion, a gradient frequency conversion control algorithm and a discrete incremental PID (proportion-integration-differentiation) control algorithm are adopted during water surface dragging, and the control target of safe, stable and accurate operation is achieved. The system automation level is improved, manual intervention is reduced, data precision and operation safety are improved, and the method is suitable for high-frequency rapid flow measurement tasks in a complex flow state and has a wide application prospect.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of water conservancy and hydrology, and particularly relates to a full-automatic sailing ADCP hydrological cableway flow measurement precise positioning system and a control method thereof. BACKGROUND

[0002] Hydrological monitoring is a key technical means for evaluating water resource conditions, predicting hydrological changes, and providing scientific basis for water resource management, flood prevention and control, environmental protection and ecological restoration by real-time monitoring and data analysis of hydrological elements such as runoff, water level and water quality. In the process of hydrological flow measurement, the cableway serves as a support platform for laying flow measurement equipment across the river channel and can work cooperatively with different types of flow measurement sensors. Early cableway flow measurement mainly relies on rotor flowmeters to obtain cross-section flow velocity, which has the disadvantages of long operation period, poor real-time performance and dependence on manual operation. With the popularization of new flow measurement technologies such as sailing ADCP, side-scan radar and video flow measurement, the combination of cableway and advanced flow measurement equipment has gradually emerged, realizing rapid scanning of the cross-section and real-time acquisition of high-precision flow velocity and flow data. Among them, the sailing ADCP has become one of the most mainstream sensing devices in the current hydrological flow measurement system due to its compact structure, high measurement accuracy and strong adaptability.

[0003] However, the current sailing ADCP flow measurement system usually relies on manual operation or unmanned ship dragging, and the operation process is complex and has not realized the automation and online of the hydrological station. Therefore, promoting the combination of sailing ADCP and automatic hydrological cableway, i.e. the combination of ADCP flow measurement technology and automatic hydrological cableway control technology, can not only significantly improve the flow measurement efficiency and shorten the operation period, but also effectively reduce human intervention, thereby improving the accuracy and reliability of data. Especially considering that hydrological stations are usually located in complex geographical environments or remote areas, the traditional manual operation method not only depends heavily on the experience and visual judgment of the operator, but also lacks accuracy, which can easily cause operation errors and even safety hazards in some extreme conditions. In this environment, relying solely on manual flow measurement is unreliable, and it is urgent to rely on automation technology to make up for this deficiency and improve the accuracy and safety of the flow measurement process.

[0004] The system described in patent application number CN202421490223.6 solves this problem well, but due to the higher accuracy requirements of automatic flow measurement than manual flow measurement, the system still has certain deficiencies. Therefore, in order to improve the stability and reliability of the walk-through ADCP automatic flow measurement system, it is particularly important to introduce control field technology. Through research in the aspects of optimization control strategy, automatic scheduling and real-time data transmission, the intelligent level of the system can be further improved. Precise control and real-time monitoring of the flow measurement equipment will realize remote operation, fault diagnosis and automatic data acquisition of the equipment, thereby providing solid technical support for the automation, intelligence and online of hydrological monitoring. This not only greatly improves the overall efficiency of the hydrological monitoring system, but also provides strong support for the efficiency and intelligence of flow measurement work. SUMMARY

[0005] The purpose of the present application is to provide a full-automatic walk-through ADCP hydrological cableway flow measurement precise positioning system and its control method to solve the problems raised in the background art.

[0006] To achieve the above purpose, the present application provides the following technical solution: a full-automatic walk-through ADCP hydrological cableway flow measurement precise positioning system, comprising: An integrated walk-through ADCP intelligent crane is used to measure hydrological data and communicates with an automatic cableway control cabinet through an Internet of Things module; An automatic cableway is composed of a shore support, a circulating cable, a lifting cable, a winch and an encoder; A driving component includes two motors and corresponding frequency converters for driving the integrated walk-through ADCP intelligent crane, which control the circulating cable and the lifting cable; characterized in that it further comprises: A water level reading module is connected to the automatic cableway control cabinet for real-time monitoring of the water level; A voice broadcast module is connected to the automatic cableway control cabinet for playing flow measurement step voice; An upper computer and a wireless control pad control the PLC and receive ADCP data through Ethernet or wireless communication; The PLC is set in the automatic cableway control cabinet and is used to regulate and control the crane's movement in the air and the water surface dragging process, and dynamically adjust the length of the vertical cable according to the detection data of the water level reading module.

[0007] Preferably, the water level reading module includes a radar water level gauge connected to the PLC through an RS interface.

[0008] Preferably, the voice broadcast module includes an embedded voice prompter, which pre-stores voice instructions and triggers playback through PLC register values.

[0009] A full-automatic walking type ADCP hydrological cableway flow measurement precise positioning control method, comprising the following steps: 1) Calibrate the flow measurement parameters, customize the ground zero point, the highest point in the air, the starting point and the segmented cable proportion coefficient, and write into the PLC; 2) Real-time calculation of the speed of the crane ship by using the sliding differential algorithm, taking the internal clock of the PLC as the timing reference, sampling the horizontal coordinate of the ADCP crane ship every 0.1s in a 0.5s time window, storing the position coordinates by using the PLC register offset, and obtaining a total of 5 continuous data points, denoted as , which are stored in the PLC registers, two control pointers and , point to , and before the action starts; Real-time calculation of the average speed of the ADCP crane ship in 0.5s , wherein is the sampling period; since the motion state of the crane ship will not change suddenly in a short time, the current ship speed is considered to be approximately equal to the average speed in the window; this calculation method is suitable for both horizontal and vertical motion of the ADCP crane ship; The speed and displacement of the crane ship in the air are controlled, including the control of the speed and the control of the displacement; Speed control: the current speed of the crane ship is calculated in real time by using the sliding differential method, and compared with the set speed upper limit , to calculate , if , the frequency converter continues to output at the current gear frequency ; if , the PLC controls the frequency converter to reduce one gear; Displacement control: the crane ship starts to move from static in the air, when the distance from the target point exceeds 20 meters, the PLC controls the corresponding frequency converter to start from 0Hz, and increases one gear every 1s, until it increases to the highest gear, and keeps uniform speed running at the highest gear; when the distance is less than 20 meters, gradient deceleration is started, until it reduces to the lowest gear that will not cause motor stall, and a inertia distance is reserved, to control the ADCP crane ship to stop moving in advance, to reduce the deviation caused by inertia; The speed and displacement of the crane ship on the water surface are controlled, including the control of the speed and the control of the displacement; Controlling the speed: real-time reading of the current water level and calculation of the current flow rate, PLC control of the current speed of the crane ship not exceeding 0.9 times the current flow rate, and once exceeding, the PLC immediately controls the frequency converter to reduce a gear; at the same time, except for the vicinity of the start and end of the dragging, the rest of the range requires the ADCP crane to move at a constant speed, the frequency converter output frequency is fixed in the middle section, and the real-time monitoring of the feedback speed is monitored in real time; Controlling displacement: when the distance from the target point exceeds 20 meters, the frequency converter starts from 0Hz, every 1 second, a gear is raised, and the current flow rate is calculated by the upper computer, the maximum frequency lower than the current flow rate is selected as the frequency converter output frequency, so that the crane ship moves at a constant speed; when the distance from the target point is less than 20 meters, the PLC controls the frequency converter to reduce the gradient to 20Hz, and uses the PID control algorithm for real-time speed regulation; when the distance from the target point is less than 5 meters, the frequency converter frequency is reduced to the lowest, and the ship is stopped at a distance of 1 meter from the target point, reducing the influence of inertia and water flow.

[0010] Preferably, the step of real-time speed regulation of the PID control algorithm is as follows: The current abscissa is , and the abscissa of the target point is ; ; The current frequency converter output frequency value is divided into 5 gears; the system output is the frequency value of the frequency converter, denoted as ; the proportional, integral, and differential coefficients of the PID control algorithm are respectively denoted as , , and b) The system output of the PID algorithm is as follows: ; c) Discretization processing, let be the sampling period, the current time is , and the system output of the PID algorithm is converted into a discrete form: ; Wherein, E(k) is the deviation value at the current time k, that is, the difference between the target value and the actual value, and E(i) is the sum of the deviation values from each time i to k; d) Write the discrete PID system in incremental form.

[0011] Let , then when : ; e) The abscissa of the target point is a known quantity, so the original formula can be written as: ; Wherein, represents the position of the horizontal coordinate at time k.

[0012] Preferably, according to the recorded position information, in order to prevent the initial segment speed from changing slowly and being difficult to detect, and in order to monitor the multi-segment displacement stable value at the stop time, three corresponding registers are selected as the corresponding monitoring objects of , and the sampling period is consistent with the speed sampling period, both being 0.1s.

[0013] Preferably, the current water level value is measured, the current water level is read in real time and compared with the water level value at the last sampling time, if the water level rises, the corresponding length of the cable in the vertical direction is received; if the water level decreases, the corresponding length of the cable in the vertical direction is released, and the tightness of the cable in the vertical direction is ensured in the required range in real time.

[0014] Preferably, the tightness of the cable is measured by a tension sensor, and the tension sensor is placed on the cable on both sides of the horizontal winch, and monitors the tension of the cable in the vertical direction and the horizontal direction respectively.

[0015] Preferably, the voice is copied into a voice prompter, the current motion state of the ADCP is judged according to the state of the current PLC, and the corresponding voice is played.

[0016] Technical effects and advantages of the present application: on the basis of increasing the water level reading module and the voice broadcast module, not only the automation and remote control of the whole flow measurement process are realized, the frequency of manual operation and human error are reduced, but also the safety and operation efficiency of the flow measurement device in complex hydrological environment are improved, and the present application is especially suitable for high-frequency, multi-section rapid flow measurement tasks; Through the combination of sliding differential control, gradient variable frequency control and discrete incremental PID control, smooth speed regulation and accurate positioning of the ADCP crane ship in the air and water surface movement process are realized, the influence of inertia and water flow disturbance on the flow measurement accuracy is significantly reduced, and the stability and reliability of the flow measurement data are greatly improved. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a schematic diagram of the full-automatic walking ADCP hydrological cableway system in the application; Figure 2 is a partial structure diagram of the air control method in the application; Figure 3 is a partial structure diagram of the water surface control method in the application. DETAILED DESCRIPTION

[0018] The following is a further description of specific embodiments of the present invention in conjunction with the accompanying drawings. It should be noted that the description of these embodiments is intended to facilitate understanding of the present invention and does not constitute a limitation of the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0019] The present invention proposes Figure 1 The fully automatic ADCP hydrographic cableway flow measurement and precise positioning system shown in the figure includes an integrated ADCP intelligent gondola, an automatic cableway and a control cabinet (including a PLC and electrical components, etc.), a wireless control pad, a flow measurement control host computer, a follow-up video monitoring device, remote control software, and video monitoring software. The automated cableway consists of shore supports, idle racks, looping cables, lifting cables, and winches. The supports are installed on both sides of the river, and the looping cables and lifting cables are installed on top of the supports. Driven by the winch, the looping cables pull the integrated ADCP intelligent gondola horizontally, while the lifting cables raise and lower the ADCP intelligent gondola. The winch mainly consists of a looping cable motor and a lifting cable motor, as well as corresponding encoders. The encoder feeds the number of motor revolutions to the automatic cableway control cabinet, providing real-time horizontal travel distance and vertical lift height of the gondola. The integrated sailing ADCP intelligent gondola is connected to the automatic cableway control cabinet and the flow measurement control host computer through the Internet of Things communication module to exchange flow measurement data and control data; the flow measurement control host computer communicates with the PLC to realize automatic control of the cableway transmission mechanism and receive and process the ADCP flow measurement data; the follow-up video monitoring equipment is connected to the flow measurement control host computer to implement follow-up monitoring of the gondola; the wireless control pad is wirelessly connected to the automatic cableway control cabinet to realize indoor and outdoor mobile flow measurement control. For details, please refer to patent application number CN202421490223.6. This system adds a water level reading module and a voice broadcast module on the basis of the system described in patent application number CN202421490223.6. The water level reading module and the voice broadcast module are both electrically connected to the control cabinet; the water level reading module includes a radar water level gauge and a switching power supply. The radar water level gauge communicates with the PLC via RS485 and uses the Modbus RTU protocol to read the current water level value every 1 second.

[0020] The present invention also provides a fully automatic navigation-type ADCP hydrological cableway flow measurement precise positioning control method, which is as follows: Build a fully automatic ADCP hydrological cableway flow measurement and precise positioning system, as follows: 1.1) Build an automated cableway and use a winch to pull an integrated ADCP intelligent gondola. 1.2) The integrated underway ADCP intelligent crane is moved and lifted by the automatic cableway, and the automatic cableway control cabinet is used to control the movement of the automatic cableway; 1.3) Build the driving part of the ADCP intelligent crane, which is composed of winch, motor and crane, where the motor is controlled by frequency converter, the number of motor is 2, which controls the vertical direction of the cableway (drives the counterweight to lift) and the horizontal direction of the cableway, and then controls the movement of the ADCP intelligent crane, the number of frequency converter is 2, each frequency converter controls one motor, which can work together or independently. Each motor is connected with an encoder, and the horizontal and vertical coordinates are determined by the counting rope length of the encoder.

[0021] Hydrological information measurement and instruction register, as follows: 2.1) According to the full-automatic underway ADCP hydrological cableway system built, scientific planning of flow measurement process is carried out, the cross section flow velocity distribution and water depth information are obtained in the process of ADCP dragging on the water surface, and the efficient measurement of water flow is realized by combining the Doppler shift principle and displacement trajectory.

[0022] 2.2) PLC and host computer are connected through Ethernet, and a fixed D register is agreed as the function code interaction area, the value of the register is 0, 1, 2, 3, 4, which corresponds to the following instructions: a) Function code 0: waiting state can execute action.

[0023] b) Function code 1: out of the warehouse and reach the specified horizontal coordinate from the air, stop after descending into the water.

[0024] c) Function code 2: stop after dragging from the water surface to the specified coordinate.

[0025] d) Function code 3: stop after returning to the warehouse.

[0026] e) Function code 4: stop after avoiding danger and rising to the highest point.

[0027] 3) Parameter calibration, as follows: 3.1) Before flow measurement, the parameters are calibrated, and the customized parameter calibration is carried out according to the difference of each hydrological station, the input method is to input the parameters in the Pad, and write into the PLC through the wireless communication module.

[0028] 3.2) Calibrate the ground zero point of flow measurement , which is the starting point of flow measurement, and the point coincides with the origin of the host computer, and the point is fixed relative to PLC and host computer during flow measurement; 3.3) Calibrate the highest point of flow measurement in the air , which is the coordinate of the starting point of the ADCP crane; the highest point in the air refers to the position of the ADCP crane in the air when the counterweight is 30 cm away from the ground after the ADCP crane is raised; 3.4) Calibrate the coordinate of the starting point of the ADCP crane , wherein the horizontal and vertical coordinates are calculated by reading the encoder readings on the horizontal and vertical motors; 3.5) Determine the total rope length At the same time, since the cable in the vertical direction will have a certain sag due to the hanging weight, it is necessary to divide the cable between the two banks into several sections for calibration, and calculate the proportional coefficient of each section Record it as a csv table and input it into Pad for saving; 3.6) Determine the warning range of the tension sensor, which is placed on the cable on both sides of the horizontal winch to monitor the tension of the vertical and horizontal cables respectively, and ensure that the cable force is within the given range; 3.7) Set the output frequency of the frequency converter to 10-50 Hz, which is divided into 5 gears, denoted as , every 10 Hz is a gear, which facilitates smooth speed regulation of the frequency converter.

[0029] 4) Plan the cable tensioning operation process and specify the flow measurement instructions, as follows: 4.1) In order to solve the problem of vertical cable being too loose or too tight due to water level change, set up a water level reading module, which includes a radar water level meter and a switching power supply. The radar water level meter communicates with the PLC through RS485, using Modbus RTU protocol, and reads the current water level value every 1 second; 4.2) Real-time read the current water level and compare it with the water level value at the last sampling time, if the water level rises, the corresponding length of the vertical cable will be collected; if the water level decreases, the corresponding length of the vertical cable will be released, to ensure that the vertical cable is within the required range; 4.3) The voice broadcast module includes a high-power embedded voice prompter and a switching power supply; copy the voice into the voice prompter in advance, determine the current motion state of the ADCP according to the current state of the PLC, and play the corresponding voice; the voice can be played singly or in groups; 4.4) The voice mainly includes the following,.mp3 files are named with numbers and stored in the voice player, and the voice is specified to be read by the write register instruction of the PLC: 4.4.1) 1. Start flow measurement; 4.4.2) 2. Start rising; 4.4.3) 3. Has reached the highest point; 4.4.4) 4. Start horizontal movement; 4.4.5) 5. Arrived at the designated location in the air; 4.4.6) 6. Start descending; 4.4.7) 7. Reach the water surface; 4.4.8) 8. Wait for the water surface to be dragged; 4.4.9) 9. Start surface towing; 4.4.10) 10. Arrived at the designated position on the water surface; 4.4.11) 11. Repurchase begins; 4.4.12) 12. Arrived at the starting point; 4.4.13) 13. Flow measurement is completed; 4.4.14) 14. Emergency avoidance; See Table 1 for details; Table 1: Process instruction table ; 5) Plan the flow measurement process and specify the flow measurement instruction interaction, as follows: 5.1) After parameter calibration is completed for the fully automated ADCP hydrographic cableway system, the ADCP gondola is placed at the starting point and flow measurement begins. 5.2) The host computer writes function code 1 and plays voice 1 and 2; the PLC controls the vertical inverter, which controls the vertical motor, causing the ADCP gondola to rise upward and reach the highest point in the air. When , the ADCP gondola is controlled to be stationary and voice 3 is played; 5.3) When the ADCP reaches After it stops, voice 4 is played; the PLC controls the horizontal frequency converter, which controls the horizontal motor, causing the ADCP gondola to move horizontally to the horizontal coordinate written by the host computer. After reaching the specified coordinate, the ADCP gondola is controlled to stop and voice 5 is played; 5.4) When the ADCP reaches the designated horizontal coordinate and comes to rest, Voice 6 is played. The PLC controls the vertical inverter, which in turn operates the vertical motor, causing the ADCP to slowly descend. When the ADCP touches the water surface, the water surface signal generator transmits a surface signal to the PLC. The PLC then controls the vertical inverter, causing the ADCP to come to rest, and Voice 7 is played. 5.5) When the ADCP gondola reaches the water surface and is stationary, the PLC writes the current vertical rope length into the register and plays voice 8; the host computer writes function code 2 and plays voice 9; the PLC controls the horizontal frequency converter, and the frequency converter controls the horizontal motor to drag the ADCP gondola on the water surface; at the same time, the PLC controls the vertical frequency converter according to the current horizontal coordinate to control the vertical motor to control the vertical rope length, so as to ensure that the ADCP gondola is always on the water surface and the rope tension is within the appropriate range; when the specified coordinate is reached, the PLC controls the two frequency converters to stop outputting, so that the ADCP gondola is stationary on the water surface, and voice 10 is played; 5.6) After each water surface dragging is completed, the ADCP gondola enters a water surface floating state, the PLC controls the vertical frequency converter according to the real-time water level to control the vertical motor to real-time correct the rope tension, so as to ensure that the ADCP gondola is in a state that can be dragged before the next command is executed; after several times of water surface dragging, the host computer calculates according to the flow measurement data to determine whether water surface dragging needs to be performed again, and the subsequent flow is divided into two cases: a) If the host computer determines that the flow measurement is incorrect, steps 5.5 and 5.6 are repeated.

[0030] b) If the host computer determines that the flow measurement is correct, a flow table is immediately generated; the host computer writes function code 3 and plays voices 11 and 2; the PLC controls the vertical motor to control the ADCP gondola to rise out of the water; when the is reached, the ADCP gondola is controlled to be stationary, voice 3 is played; after a delay of 3 seconds, voice 4 is played, the PLC controls the horizontal motor to perform horizontal movement, and after moving to the starting point directly above, the gondola is controlled to be stationary, voice 5 is played; after a delay of 3 seconds, voice 6 is played, the PLC controls the vertical frequency converter, and the frequency converter controls the vertical motor to slowly lower the ADCP gondola, and after finally landing at the starting point, the gondola is stationary, voice 12 is played. The flow measurement is completed, and voice 13 is played. 5.7) At any time during the flow measurement, once an emergency situation is encountered, such as a passing ship, an obstacle, and a flow error, the host computer writes function code 4 into the specified register of the PLC, and voice 14 is played; the PLC immediately stops the current operation flow, delays for 3 seconds, and then plays voice 2; the PLC controls the vertical frequency converter, and the frequency converter quickly adjusts the frequency to the highest frequency output to control the motor to make the ADCP gondola rise to the point and stop, and voice 3 is played; the host computer waits for the next instruction according to the on-site situation.

[0031] 6) Control of the gondola, which is as follows: 6.1) According to the operation flow, motion control is required during each motion process, and the speed and displacement of the ADCP gondola are taken as the research objects, and the desired control effect is as follows: a) The speed of the ADCP crane is controlled within a specified range, and shall not exceed the current water flow rate according to the hydrological requirements; meanwhile, the speed of the ADCP crane shall not be suddenly changed, otherwise, accidents such as overturning may occur; b) The ADCP crane is close to the target point at the end of each movement, and the impact of inertia on the motor is minimized; 6.2) To improve the continuous recording and real-time analysis capability of the PLC for the movement state of the ADCP crane under resource-limited conditions, the sliding differential method is used to calculate the speed: taking the internal clock of the PLC as the timing reference, the horizontal coordinate of the ADCP crane is sampled every 0.1s within a time window of 0.5s, the position coordinates are stored using the PLC register offset, and a total of 5 consecutive data points are obtained, denoted as , which are stored in the PLC registers; two control pointers and are set, where points to , points to ; 6.3) The average speed of the ADCP crane within 0.5s is calculated in real time , where is the sampling period. Due to the limited number of registers, a loop structure is used, where the pointer points to , and in the next sampling period, the pointer points to , and the value written to the register each time covers the previous value; since the movement state of the crane does not change suddenly within a short period of time, the current speed is considered to be approximately equal to the average speed within the window; this calculation method is also applicable to the horizontal and vertical movements of the ADCP crane; 6.4) The speed and displacement of the ADCP crane during air movement are controlled, and the main concern during air movement is safety. The main steps are as follows: a) Control the speed; to prevent accidents such as overturning of the ADCP ship due to sudden changes in speed, the frequency converter is required to perform smooth speed regulation, and shall not suddenly increase or decrease the frequency; the sliding differential control algorithm is used to control the speed of the ADCP crane during air movement, as shown in Figure 2 , the current speed of the crane is calculated in real time by the sliding differential method, and compared with the set speed upper limit , and is calculated; if , the frequency converter continues to output at the current gear frequency ; if , the PLC controls the frequency converter to decrease by one gear, ensuring smooth and safe operation of the crane, and reducing system impact and inertia errors; b) Controlling displacement: The ADCP gondola starts moving from a standstill in the air. To precisely stop at the designated location, when the distance from the target point exceeds 20 meters, the PLC controls the corresponding frequency converter, starting from 0Hz and increasing one gear every 1 second until it reaches the highest gear, and maintains a constant speed at the highest gear. When the distance is less than 20 meters, a gradient deceleration is initiated, decreasing one gear every 2 seconds until it reaches the lowest gear that does not cause the motor to stall at 2 meters from the target point. A certain inertia distance is reserved to control the ADCP gondola to stop in advance and reduce its deviation due to inertia. 6.5) Control the speed and displacement of the ADCP gondola while it is moving on the water surface. The main concern during the surface dragging process is accuracy. The main steps are as follows: a) Speed ​​control: To meet ADCP flow measurement requirements, the host computer reads the current water level and calculates the current flow rate in real time. The PLC controls the movement speed of the ADCP gondola to not exceed 0.9 times the current flow rate. If it exceeds this, the PLC immediately controls the inverter to reduce one gear. In addition, except for the range near the start and end of the dragging, the ADCP gondola is required to move at a constant speed throughout the rest of the range. In the intermediate range, the inverter output frequency is fixed, and the feedback speed is monitored in real time. b) Control displacement. After receiving the surface drag command, the PLC determines that when the distance from the target point exceeds 20 meters, the inverter is controlled to start from 0Hz and increase one gear every 1 second. The host computer calculates the current flow rate and selects the maximum frequency below the current flow rate as the inverter output frequency, so that the ADCP gondola moves at a constant speed. When the distance from the target point is less than 20 meters, the PLC controls the inverter to gradually reduce the speed to 20Hz and use a discrete incremental PID control algorithm for real-time speed regulation. When the distance from the target point is less than 5 meters, the current speed is monitored to ensure that the inverter frequency is slow. If it is slow, the inverter frequency is reduced to the minimum and the vessel is stopped about 1 meter away from the target point to reduce the influence of inertia and water flow. 6.6) If Figure 3 As shown in the figure, when the ADCP gondola is less than or equal to 20 meters away from the target point, in order to achieve stable and accurate approach to the target, the system introduces a PID closed-loop speed control mechanism. It should be noted that the boundary distance D of the PID algorithm is set to 20 meters. When the distance is greater than D, there is no need to use PID fine tuning. Just fix the input, the main steps are as follows: a) Definition: The current horizontal coordinate is , the horizontal coordinate of the target point is ; ; The current inverter output frequency value is divided into 5 levels; fixed frequency is the middle frequency, and the system output is the frequency value of the inverter, which is recorded as ; The proportional, integral, and differential coefficients of the PID control algorithm are respectively recorded as ; b) The system output of the PID algorithm is as follows: ; c) However, in the actual process, the changes of the system at each moment are uncertain and are of concern to users, so it is discretized in actual use; let is the sampling period, and the current time is , then the system output implemented by the PID algorithm can be converted into discrete form: ; d) Due to the limited memory resources of the PLC, the need for smooth frequency modulation of the inverter and the small sampling period, the discrete PID system is written in incremental form; make , then when hour: ; e) The horizontal coordinate of the target point is a known quantity, so the original formula can be written as: ; f) According to the recorded In order to prevent the initial segment speed from changing too slowly and being difficult to detect, and to monitor the multi-segment displacement stability value at the stop moment, select

[0032] The corresponding three registers are The corresponding monitoring object, at the same time, the sampling period is consistent with the speed sampling period, both of which are 0.1s; g) Proportional coefficient It is necessary to calibrate according to the specific conditions of each hydrological station, and the proportional coefficient of each area is calibrated on site; under the premise of the previous steps, determine After the value of , the current At the same time, it should be stipulated The value range of the inverter is to prevent the frequency from changing suddenly or exceeding the frequency range.

[0033] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A fully automatic navigation ADCP hydrological cableway flow measurement and precise positioning system, including: An integrated ADCP intelligent gondola is used to measure hydrological data and communicate with the automatic cableway control cabinet via an IoT module; Automated cableway, consisting of shore supports, loop ropes, lifting ropes, winches and encoders; The drive components include two motors and corresponding inverters for controlling the circulating and lifting cables, which are used to drive the integrated ADCP intelligent gondola; It is characterized by further comprising: The water level reading module is connected to the automatic cableway control cabinet to monitor the water level in real time; The voice broadcast module is connected to the automatic cableway control cabinet and is used to play the voice of the flow measurement steps; The host computer and wireless control pad control the PLC and receive ADCP data via Ethernet or wireless communication; The PLC, installed in the automatic cableway control cabinet, is used to control the aerial movement of the gondola and the towing process on the water surface, as well as dynamically adjust the length of the vertical cable according to the detection data of the water level reading module.

2. A fully automatic underway ADCP hydrological cableway flow measurement and precise positioning system according to claim 1, characterized in that: The water level reading module includes a radar water level meter, which is connected to the PLC via an RS interface.

3. The fully automatic ADCP hydrographic cableway flow measurement and precise positioning system according to claim 1 is characterized by: The voice broadcast module includes an embedded voice prompter, pre-stored voice instructions, and the playback is triggered by the PLC register value.

4. A fully automatic navigation ADCP hydrological cableway flow measurement precise positioning control method, characterized in that: The following steps are involved: 1) Calibrate the flow measurement parameters, customize the ground zero point, the highest point in the air, the starting point and the proportional coefficient of the segmented cable, and write them into the PLC; 2) The sliding difference algorithm is used to calculate the gondola speed in real time. The internal clock of the PLC is used as the timing reference. The horizontal coordinate of the ADCP gondola is sampled every 0.1s within a time window of 0.5s. The position coordinate is stored using the PLC register offset. A total of 5 consecutive data points are obtained, which are recorded as , corresponding to the storage in PLC registers, two control pointers and Before the action starts point to , point to ; Real-time calculation of the average speed of the ADCP gondola within 0.5s ,in is the sampling period; since the motion state of the gondola will not mutate suddenly in a short time, the current ship speed is considered to be The average speed within the window Approximately equal; this calculation method is applicable to both horizontal and vertical movements of the ADCP gondola; 3) Control the speed and displacement of the gondola during aerial movement, including speed control and displacement control; Speed ​​control: The current speed of the gondola is calculated in real time by the sliding difference method and compared with the set speed limit. Compare and calculate ,like , the inverter will follow the current gear frequency Continue output; if , then the PLC controls the inverter to shift down one gear; Controlling displacement: The gondola starts moving from a standstill in the air. When it is more than 20 meters away from the target point, the PLC controls the corresponding frequency converter to start from 0Hz and increase one gear every 1 second until it reaches the highest gear, and maintains a constant speed at the highest gear. When the distance is less than 20 meters, it begins to decelerate gradually until it reaches the lowest gear that does not cause the motor to stall. In addition, an inertia distance is reserved to control the ADCP gondola to stop in advance and reduce its deviation due to inertia. 4) Control the speed and displacement of the gondola when it moves on the water surface, including speed control and displacement control; Speed ​​control: The current water level is read in real time and the current flow rate is calculated. The PLC controls the current gondola's movement speed to not exceed 0.9 times the current flow rate. If it exceeds this, the PLC immediately controls the inverter to reduce one gear. At the same time, except for the start and end of dragging, the ADCP gondola is required to move at a constant speed. In the intermediate period, the inverter output frequency is fixed, and the feedback speed is monitored in real time. Control the displacement: when the distance to the target point exceeds 20 meters, the frequency converter is controlled to start from 0Hz and increase one gear every 1 second. The host computer calculates the current flow rate and selects the maximum frequency lower than the current flow rate as the frequency converter output frequency to make the gondola move at a constant speed. When the distance to the target point is less than 20 meters, the PLC controls the frequency converter to gradually reduce the speed to 20Hz and uses the PID control algorithm for real-time speed regulation. When the distance to the target point is less than 5 meters, the frequency converter frequency is reduced to the minimum and the gondola is stopped 1 meter away from the target point to reduce the influence of inertia and water flow.

5. A fully automatic navigation-type ADCP hydrographic cableway flow measurement precise positioning control method according to claim 4, characterized in that: The steps of real-time speed regulation of the PID control algorithm are as follows: The current horizontal axis is , the horizontal coordinate of the target point is ; ; The current inverter output frequency value is divided into 5 levels; the system output is the inverter frequency value, recorded as ; The proportional, integral, and differential coefficients of the PID control algorithm are respectively recorded as , It means that historical error eliminates steady-state deviation; b) The system output of the PID algorithm is as follows: ； c) Discretization processing, let is the sampling period, and the current time is , the system output implemented by the PID algorithm is converted into discrete form: ； Where E(k) is the deviation value at the current moment k, that is, the difference between the target value and the actual value, and E(i) is the sum of the deviation values ​​from each moment i to moment k; d) Write the discrete PID system in incremental form; make , then when hour: ; e) The horizontal coordinate of the target point is a known quantity, so the original formula can be written as: ； in, Indicates the position of the horizontal axis at time k.

6. A fully automatic navigation-type ADCP hydrographic cableway flow measurement precise positioning control method according to claim 4, characterized in that: According to the recorded In order to prevent the initial segment speed from changing too slowly and being difficult to detect, and to monitor the multi-segment displacement stability value at the stop moment, select The corresponding three registers are The corresponding monitoring object, at the same time, the sampling period is consistent with the speed sampling period, both of which are 0.1s.

7. The method for precise positioning control of fully automatic ADCP hydrographic cableway flow measurement according to claim 4, characterized in that: Measure the current water level value, read the current water level in real time and compare it with the water level value at the last sampling moment. If the water level rises, the corresponding length of cable in the vertical direction should be retracted; if the water level drops, the corresponding length of cable in the vertical direction should be released, ensuring in real time that the tightness of the vertical cable is within the required range.

8. The method for precise positioning control of fully automatic ADCP hydrographic cableway flow measurement according to claim 7, characterized in that: The tightness of the cable is measured by tension sensors, which are placed on the cables on both sides of the horizontal winch to monitor the vertical and horizontal cable tensions respectively.

9. The method for precise positioning control of fully automatic ADCP hydrographic cableway flow measurement according to claim 4, characterized in that: Copy the voice into the voice prompter, judge the current motion state of ADCP according to the current PLC state, and play the corresponding voice.

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